The invention concerns a potato harvesting machine or a processing machine which is provided with a separating device for removing clods, rocks, haulm and the like entrained admixtures from the picked-up crop-containing mixture. A conveying device supplies the substantially compact mixture as a conveyed stream, from where the mixture, moved into the area of a drop stage and, in the process, being affected by means of a conveying medium in the form of an air stream, can be separated, wherein, downstream of the drop stage that is effecting loosening of the mixture, at least one retaining element is provided that is oriented so as to face the falling mixture and is interacting with the at least one air stream in such a way that at least the crop and the solid bodies can be separately conveyed, away from the retaining device, as sorted individual parts in substantially oppositely oriented conveying directions, respectively.
Different method variants are known for machines and devices for root crop treating and processing, in particular potato harvesting machines. In particular for separation of potatoes and similar crop from a picked-up soil mixture with clods, rocks, similar solid bodies as well as fibrous admixtures, different concepts of mechanical separating devices with belts and screens are used (company brochure Grimme Landmaschinenfabrik GmbH & Co. KG, Damme; “Produktprogramm” (translation: product line); GEN.00283, Aug. 13, 5000; Erntetechnik (translation: harvesting technology); pp 14 to 23).
In a solution according to CA 2 880 593 A1 for affecting the mixture that has been picked up by a potato harvesting machine, an air stream is additionally utilized which is acting in the area of a retaining element onto the goods to be separated that are moved by a conveyor across a drop stage. This air stream is directed onto the mixture that is present in loosened form in the area of the retaining element so that, in the area of a fluidic separating bed, assistance is provided for a further activated transport of crop and solid bodies in oppositely extending conveying directions.
EP 1 133 909 A2 discloses a root crop harvesting machine that comprises a system with several belt conveyors. The latter can be pivoted into variable active positions. A fluidic separation is not provided in any of the conveying areas.
A conveying device for beets according to DE 43 38 477 A1 comprises rod conveyor belts operating as steep conveying devices so that, in combination with flat conveyors, the cleaning process is improved. A fluidic separation is not provided in this device.
The invention has the object to design a potato harvesting machine provided with a fluidic separating device in such a way that with minimal technical expenditure the operation of the machine can be retrofitted in accordance with changing harvesting conditions and, in this way, an optimal mixture separation is enabled at reduced energy expenditure.